Objective: Peritonitis is still one of the major causes of peritoneal dialysis (PD) patients' dropout. In the present study, we analyzed the relationship between gastrointestinal (GI) problems and peritonitis in our CAPD patients. Methods: It is a prospective observational study. In December, 2008, 158 patients on continuous ambulatory peritoneal dialysis (CAPD) for more than 3 months from our PD unit were included in this study. A questionnaire was used to evaluate their GI symptoms score (GISS). All patients were followed up for 24 months or until they dropped out from our PD program. All peritonitis events were recorded. Results: The patients' PD duration was 22 (4 - 132) months before the study. During the 24 months follow-up, 37 patients dropped out. And 37 patients had 46 episodes of peritonitis (peritonitis group) whereas the other 121 patients did not have peritonitis (peritonitisfree group). The overall peritonitis rate was one episode per 75.87 patient months. The peritonitis free group had lower GISS (1.35 ± 1.94 vs. 2.95 ± 3.19, p = 0.006), higher albumin level and longer dialysis duration at baseline as compared to the peritonitis group. Multivariate Cox-regression analysis showed that only GISS (OR 1.206, 95% CI 1.093 - 1.330) and dialysis duration (OR 1.018, 95% CI 1.006 - 1.031) were the risk factors for the time to first peritonitis episodes during the follow-up. Further analysis identified 2 GISS components, belching and constipation, as the strongest predictors of peritonitis during the follow-up period (p < 0.005). Conclusion: Our study showed that GI symptoms could predict peritonitis in CAPD patients. Prevention and treatment for GI problems may thus be helpful to decrease peritonitis rate.